From FPL's site (Florida Power and Light): It's $651.49 if you want your own house line buried by FPL plus whatever an electrician would charge for the associated work. However- "For system reliability reasons, FPL will only convert the (your personal) system to underground if one full block or more is converted at the same time. FPL's typical underground system is a "looped" system, which means power can be supplied to the same transformer from two different directions. Depending on the location, more than one block may need to be converted in order to complete this "loop." On a bigger scale- "The two key drivers contributing to the cost calculations are labor and materials. Depending on these factors, underground facilities can cost anywhere from $500,000 per mile to more than $4 million per mile." But the conversion task for neighborhoods isn't hopeless: "Already more than one-third of the neighborhood power lines in FPL’s system are underground." It just takes investment, and FPL has been shy about doing it for far too long. Not an impossible task.